The 28 anxious EU leaders are gathering in the Bulgarian capital for discussions over dinner on Wednesday on how to salvage the nuclear deal and European business dealings with Iran from Trump's sanctions and how to avoid a trade war in an escalating tariff dispute with the United States.
"But frankly speaking, Europe should be grateful to President Trump, because thanks to him we have got rid of all illusions". He has made us realize that if you need a helping hand, you will find one at the end of your arm.
The head of the bloc's executive, Jean-Claude Juncker of the European Commission, will also present options the leaders have to shield European investments in Iran and the slowly-reviving economic cooperation, which many EU states hope to benefit from.
Tusk pled Trump not to withdraw from the Paris Climate Agreement and "change the (political) climate for the worse".
In a scathing attack, former Polish prime minister Tusk compared the Trump administration with Europe's long-time adversaries, Moscow and Beijing.
Tusk said the European Union must be more united than ever before to deal with what he called Trump's "capricious assertiveness". To put it simply: either we are together, or we will not be at all.
"Europe must do everything in its power to protect, in spite of today's mood, the transatlantic bond".
"The extra-territorial dimension of US sanctions is unacceptable". Tusk said he wanted Europe to "stick to our guns" and described Trump's justification of tariffs on the basis of national security as "absurd". Therefore US tariffs can not be justified on the basis of national security.
Trump said the tariffs are needed for national security reasons.
In dinner talks in the Bulgarian capital of Sofia, EU leaders will be briefed on possible incentives to keep Tehran in the nuclear agreement, even after the U.S. pulled out.
The EU has called for "utmost restraint" after Israeli forces killed 60 Palestinians during clashes and protests along the Gaza border against the opening of the United States embassy in Jerusalem, the conflict's bloodiest day in years.
"We notably discussed concrete practical solutions to make sure the European Union can continue to live up to its commitments under the deal and protect our economic operations", said Avramopoulos, the EU's migration commissioner.